Just to try out a theory to make sure it's working correctly. I changed the sketch on one ESP8266 sensor so that the MQTT server IP was the same as the new Pi Zero W when I type ifconfig
// Connect to the WiFi
const char* ssid = "PiCharts";
const char* password = "Espressif";
const char* mqtt_server = "192.168.4.1";
It does log on and works correctly. So my issue now is NOT with MQTT but assigning the Pi Zero W's IP address to match the IP address from the previous Pi Zero W. Just so I'm not pulling apart a bunch of sensors to change the IP address in the individual sketches.
I did it with this tutorial: https://www.raspberrypi.org/documentati ... s-point.md
Two lines that I'm looking at :
sudo nano /etc/dhcpcd.conf
sudo nano /etc/dnsmasq.conf
interface=wlan0 # Use the require wireless interface - usually wlan0
Not sure if I even need the dnsmasq.conf file unless each ESP loging in will be assigned an IP while it's logged in.
I definitely need to change the Static ip_address=169.254.78.169 so all my sensors can log into MQTT
So it's down to; what to do with the dnsmasq.conf?